Proprietary board drivers (such as the Allen Bradley KTX card, Modicon SA85 card, Siemens TIWAY card, and so on) have their own low-level drivers. Each driver has debugging parameters to make it easier to debug device behavior. Check the CitectSCADA Knowledge Base and Help for parameters. The Knowledge Base has articles describing how to debug these board drivers.
The debugging process is exactly the same as with a serial connection: